adding docker compose tutorial

Creating-Docker-Compose/learn-docker-compose-tutorial-readme.md

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+# 🐳 Contribution: Docker Compose Tutorial
+
+This tutorial explains how to use **Docker Compose** — a tool that helps you manage multi-container Docker applications easily with a single YAML file.
+
+---
+
+## 🚀 What is Docker Compose?
+
+Docker Compose helps you:
+- Define **multiple containers** and their relationships in one `docker-compose.yml` file.
+- Start, stop, and rebuild all your services with a single command.
+- Manage environment variables, networks, and volumes efficiently.
+
+---
+
+## 🧩 Basic `docker-compose.yml` Structure
+
+Here’s a minimal example:
+
+```yaml
+name: project-name
+
+services:
+  web:
+    image: nginx:latest
+    ports:
+      - "8080:80"
+    volumes:
+      - ./html:/usr/share/nginx/html
+
+  app:
+    build: ./app
+    environment:
+      - APP_ENV=local
+    depends_on:
+      - db
+
+  db:
+    image: mysql:8
+    environment:
+      MYSQL_ROOT_PASSWORD: secret
+      MYSQL_DATABASE: app_db
+    volumes:
+      - db_data:/var/lib/mysql
+
+volumes:
+  db_data:
+```
+
+---
+
+## 🧠 Commands You Should Know
+
+| Command | Description |
+|----------|-------------|
+| `docker compose up` | Starts all services defined in the file |
+| `docker compose up -d` | Starts in detached mode (background) |
+| `docker compose down` | Stops and removes containers, networks, and volumes |
+| `docker compose build` | Builds images for services |
+| `docker compose logs` | Shows logs for all services |
+| `docker compose ps` | Lists running services |
+
+---
+
+## ⚙️ Using Environment Variables
+
+You can store configuration in a `.env` file:
+
+```bash
+MYSQL_ROOT_PASSWORD=secret
+MYSQL_DATABASE=app_db
+```
+
+Docker Compose automatically loads this file to set environment variables.
+
+---
+
+## 🧹 Cleaning Up
+
+To remove containers and networks created by Docker Compose:
+
+```bash
+docker compose down
+```
+
+To also remove volumes and images:
+
+```bash
+docker compose down --volumes --rmi all
+```
+
+---
+
+## 💡 Pro Tips
+
+- Use `depends_on` to control startup order of containers.
+- Use named volumes for persistent data.
+- Use `.env` files for secrets and configuration.
+- Version control your `docker-compose.yml` with your project.
+
+---
+
+## ✅ Summary
+
+Docker Compose simplifies managing multiple containers — one file, one command, full control.
+
+You can run:
+```bash
+docker compose up -d
+```
+and have your **entire application stack** up in seconds!